French Drains and Surface Water Management
Water is the reason most hard surfaces fail. It undermines driveways, lifts patios through freeze and thaw, washes out the base under slabs and finds its way into foundations. Because we build driveways and patios, we deal with the water moving around them rather than treating drainage as a separate trade.
What a French drain is and what it does
A French drain is a trench containing perforated pipe surrounded by washed stone and wrapped in filter fabric. Water in the surrounding soil takes the path of least resistance into the stone, enters the pipe and is carried to somewhere it can safely discharge.
The details decide whether it works for twenty years or clogs in three. The stone has to be clean and washed rather than crusher run with fines in it. The fabric has to wrap the stone to keep silt out. The pipe has to run at consistent fall to a real outlet.
A pipe laid in dirt without stone and fabric is not a French drain. It silts up and stops working, usually within a couple of seasons.
Drainage problems around hard surfaces
Water running down a driveway toward a garage. This is a grading problem, and the fix is usually a trench drain across the apron connected to a proper outlet.
Base washout under driveways and patios, where water moving through the ground carries fine material away and leaves voids. The slab then settles or cracks into them.
Water collecting against foundations, frequently caused by downspouts discharging next to the house or by grade that falls back toward it. This is the most expensive problem on the list to ignore.
Retaining walls without drainage behind them. Saturated soil exerts far more pressure than dry soil, and hydrostatic pressure is the main reason walls fail.
Where the water has to go
Every drainage system needs a legal, workable discharge point, and this is where a lot of installations fail. Options include daylighting to a lower point on the property, a dry well sized for the volume, or a connection where a municipal system permits it.
Discharging onto a neighbouring property is not a solution and creates a liability. Some townships regulate stormwater discharge and require approval.
We work out where the water is going to end up before quoting a system to move it there.
Other drainage & hardscape we handle
Retaining Walls
Block and poured retaining walls with the drainage that keeps them standing.
Retaining Walls detailsPaver Patios
Segmental paver patios, walkways and driveway aprons on a properly compacted base.
Paver Patios detailsFrench Drains by town
French Drains questions
How much does a French drain cost to install?
Cost depends on length, depth, how difficult the excavation is and where the discharge point ends up. A short run to daylight on an accessible slope is a modest job. A long run requiring a dry well, or one crossing established landscaping and hard surfaces, costs considerably more.
The discharge point is the variable people underestimate. Moving water into a trench is straightforward. Getting it somewhere it can legally and permanently go is what drives the number.
How long does a French drain last?
A properly built one with washed stone, filter fabric and consistent fall can work for decades.
Ones that fail early almost always share the same faults: unwashed stone with fines that clog the voids, no filter fabric so silt migrates in, or insufficient fall so water sits in the pipe instead of moving.
Why does water pool on my driveway or patio?
Either the surface was not pitched correctly when it was built, or a section has settled since. Both leave a low spot with nowhere for water to go.
Standing water is not just a nuisance. On asphalt it accelerates surface failure, on concrete it drives freeze and thaw damage, and in winter it becomes ice. The fix depends on whether the whole surface is mis-graded or one area has sunk, which needs looking at.
Will a French drain fix a wet basement?
An exterior French drain can substantially reduce water reaching a foundation, and combined with correcting grade and extending downspouts it resolves a lot of basement moisture problems.
It is not universal. Water entering through a cracked foundation wall, or rising groundwater below slab level, needs interior waterproofing or a sump system instead. We will tell you if what you are describing is outside what exterior drainage can fix.
Get a free estimate
Send a few photos of the driveway, patio or drainage problem and we will come back with a real number, not a range.
- Most estimates come back within one business day.
- Photos usually get you a real number without a site visit.
- If you need less work than you asked about, we will say so.
Prefer to talk? (610) 646-1187